Tobacco constituent releasing components

ABSTRACT

The invention relates to tobacco constituent releasing components for inclusion in an aerosol provision device, the tobacco constituent releasing component including tobacco particles, optionally in an agglomerated structure. The invention also relates to apparatus including the tobacco constituent releasing components and to methods of manufacturing the tobacco constituent releasing components.

TECHNICAL FIELD

The invention relates to tobacco constituent releasing components for inclusion in an aerosol provision device, such as an apparatus for heating smokeable material to volatilise at least one component of the smokeable material, the tobacco constituent releasing component including tobacco particles, optionally in an agglomerated structure. The invention also relates to apparatus including the tobacco constituent releasing components and to methods of manufacturing the tobacco constituent releasing components.

BACKGROUND

Smoking articles such as cigarettes, cigars and the like burn tobacco during use to create tobacco smoke. Attempts have been made to provide alternatives to these articles by creating products that release compounds without combusting. Examples of such products are so-called “heat not burn” products or tobacco heating devices or products, which release compounds by heating, but not burning, smokeable material.

It is also known to include flavours in smoking articles to add specific desirable flavours to the aerosol generated by the smoking article. This has been achieved in a variety of different ways, including the use of crushable capsules that contain flavour compositions.

SUMMARY

According to a first aspect of the invention, there is provided a tobacco constituent releasing component for inclusion in an aerosol provision device, the tobacco constituent releasing component having an agglomerated structure formed from a precursor composition comprising tobacco particles, wherein the pH of the precursor composition has been adjusted to a basic pH.

In some embodiments the pH is increased by the addition of one or more bases or a basic buffer system.

Alternatively, there is provided a tobacco constituent releasing component for inclusion in an aerosol provision device, the tobacco constituent releasing component comprising tobacco particles and one or more bases or a basic buffer system, the tobacco constituent releasing component having a basic pH.

In some embodiments the one or more base is selected from the group consisting of hydroxides, carbonates and hydrogen carbonates. In some embodiments the one or more base is selected from the group consisting of: potassium hydroxide, sodium hydroxide, sodium carbonate and sodium bicarbonate.

In some embodiments the pH of the precursor composition is at least about 7.5.

In some embodiments the tobacco particles have an average diameter no greater than 3 mm, no greater than 1 mm, no greater than 0.5 mm, or no greater than 0.3 mm.

In some embodiments one or more aerosol forming agent is included. In some is embodiments the aerosol forming agent is selected from the group consisting of glycerol, propylene glycol and glyceryl triacetate.

In some embodiments one or more binder is included. In some embodiments the one or more binder is selected from the group consisting of: thermoreversible gelling agents, such as gelatin; starches; polysaccharides; pectins; celluloses; cellulose derivatives, such as carboxymethylcellulose; and alginates.

In some embodiments one or more flavour-modifier is included.

In some embodiments the precursor composition is granulated or spheronised to form the agglomerated structure.

In some embodiments the precursor composition is extruded to form the agglomerated structure.

In some embodiments the components are in the form of granules.

In some embodiments the components have an elongated or rod-shaped form.

In some embodiments the components have a cross sectional shape to increase the surface area of the tobacco constituent releasing component.

According to a second aspect of the invention, there is provided an aerosol provision device comprising a tobacco constituent releasing component according to the first aspect of the invention.

In some embodiments the device is a tobacco heating product comprising a tobacco segment which is to be heated to volatilise constituents, and optionally including a filter or filter element.

In some embodiments the device is a Hybrid product comprising a tobacco segment which is to be heated to volatilise constituents, and a liquid which is to be heated to form a vapour, and optionally including a filter or filter element.

In some embodiments the tobacco constituent releasing component is located in a filter or filter element of the device. In some embodiments one or more tobacco constituent releasing components are surrounded by filter material in the filter or filter element. In other embodiments one or more tobacco constituent releasing components are located in a cavity of a multi-segment filter.

In some embodiments one or more tobacco constituent releasing components are located in the tobacco segment. In some embodiments the tobacco segment consists of one or more tobacco constituent releasing components.

In some embodiments the device is a Hybrid product comprising a tobacco segment which is to be heated to volatilise constituents, and a liquid which is to be heated to form a vapour, wherein one or more tobacco constituent releasing components are located in the tobacco segment and wherein the tobacco segment is heated by the vapour. In some embodiments, the liquid is a nicotine-free liquid. In some embodiments, the device includes a means for heating the liquid to form a vapour, but does not include a separate means for heating the smokeable material.

According to a third aspect of the invention, there is provided a method of manufacturing a tobacco constituent releasing component, comprising preparing a precursor composition comprising tobacco particles; adjusting the pH of the precursor composition to a basic pH; and treating said precursor composition to form an agglomerated structure.

In some embodiments the precursor composition is granulated or spheronised to form the agglomerated structure.

In some embodiments the precursor composition is extruded to form the agglomerated structure. In some embodiments the extruded agglomerate is cooled during or after extrusion. In some embodiments the extrusion creates inner channels within the extruded agglomerate.

According to a fourth aspect of the invention, there is provided an apparatus for heating smokeable material to volatilise at least one component of the smokeable material, and a nicotine-free liquid which is to be heated to form a vapour, wherein the smokeable material comprises tobacco particles having a basic pH, and wherein the smokeable material is heated by the vapour.

In some embodiments the apparatus includes a means for heating the liquid to form a vapour, but does not include a separate means for heating the smokeable material.

In some embodiments the pH is increased by the addition of one or more bases or a basic buffer system.

In some embodiments the pH of the tobacco particles is at least about 7.5.

In some embodiments the tobacco particles have an average diameter no greater than 3 mm, no greater than 1 mm, no greater than 0.5 mm, or no greater than 0.3 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to accompanying drawings, in which:

FIG. 1 is a flow chart showing key steps of a process according to embodiments of the present invention;

FIGS. 2a, 2b and 2c show examples of nozzle designs for forming extruded agglomerates having inner channels, whilst FIGS. 2d and 2e show how such nozzles may be used to shape the extruded agglomerates;

FIG. 3 is a photograph of some extruded agglomerates, showing different cross-sectional geometries forming inner channels;

FIG. 4a shows an example of a die used to produce granules by extrusion, whilst

FIG. 4b shows how such a die may be used to form the extruded agglomerates;

FIG. 5 is a schematic representation of some extruded granules;

FIG. 6 is a schematic cross-sectional view of a tobacco heating product for heating smokeable material to volatilise at least one component of the smokeable material including a tobacco constituent releasing component;

FIG. 7 is a schematic view of a Hybrid device for heating smokeable material to volatilise at least one component of the smokeable material including a tobacco constituent releasing component; and

FIG. 8 is a schematic cross-sectional view of an example of a cartridge containing multiple tobacco constituent releasing components.

DETAILED DESCRIPTION

The invention relates to tobacco constituent releasing components that are formed from tobacco particles. These components are able to release tobacco constituents including flavours and nicotine, for example when heated.

At least some of the released constituents are directly derived from the tobacco particles used to form the components. In some embodiments, further materials may be added to the components for release. These further materials may, for example, also comprise tobacco constituents added to supplement those directly derived from the tobacco particles. Alternatively or in addition, the further materials added to the components for release may not be derived from tobacco. For example, the components may also, in some embodiments, carry and release other flavours, including those not derived from tobacco.

In some embodiments, the tobacco constituent releasing components are agglomerated structures. This means that they are a mass or cluster formed by fusing or adhering multiple particles to one another. The constituent particles include tobacco particles. In some embodiments, particles of other materials may also be included.

pH Adjustment

In some embodiments, the agglomerated structures are formed from a precursor composition comprising tobacco particles, wherein the pH of the precursor composition has been adjusted to a basic pH. For example, the pH may be adjusted to at least about 7.5. The pH may be adjusted by the addition of one or more bases. Alternatively, the pH may be adjusted by the use of a buffer solution.

In some embodiments, the tobacco constituent releasing component comprises tobacco particles and one or more bases or a basic buffer system, so that the tobacco constituent releasing component has a basic pH. For example, the pH may be at least about 7.5.

The purpose of adjusting the pH of the tobacco particles and/or of the precursor composition is to provide the tobacco constituents in a chemical form which means that they are readily released from the releasing component, and/or they are readily transferred to the aerosol generated by the smoking article. Adjusting the pH of tobacco changes the natural balance of those acid-base reactions that bind certain classes of chemicals within the tobacco. For example, in natural tobacco leaf, nicotine tends to bind with organic acids that are present in the leaf and hence is more stable is and less likely to volatilise when exposed to mild heat. If the pH of the leaf is raised, this reduces the nicotine's natural association with the acids. Such unbound of “free” nicotine is more volatile. The same principle applies to other chemical equilibria within tobacco.

In some embodiments, the pH of the precursor composition is adjusted to at least about 7.5, at least about 8, at least about 8.5, at least about 9, at least about 9.5 or at least about 10. In some embodiments, the pH is adjusted to no higher than about 14, no higher than about 13.5, no higher than about 13, no higher than about 12.5, no higher than about 12, no higher than about 11.5, no higher than about 11, no higher than about 10.5 or no higher than about 10. In some embodiments, the pH of the precursor composition is adjusted to from about 8 to about 10, or from about 8.5 to about 9.5.

In some embodiments, the pH of the tobacco constituent releasing component is at least about 7.5, at least about 8, at least about 8.5, at least about 9, at least about 9.5 or at least about 10. In some embodiments, the pH is no higher than about 14, no higher than about 13.5, no higher than about 13, no higher than about 12.5, no higher than about 12, no higher than about 11.5, no higher than about 11, no higher than about 10.5 or no higher than about 10. In some embodiments, the pH of the tobacco constituent releasing component is adjusted to from about 8 to about 10, or from about 8.5 to about 9.5.

In some embodiments, the pH is adjusted to from about 7.5 to about 10, or from about 8 to about 9, or to about 8.5, about 9, about 9.5 or about 10.

In some embodiments, the base used to adjust the pH is a hydroxide or a carbonate. Hydroxides used may be monoacidic bases, diacidic bases or triacidic bases. Suitable bases include, for example, potassium hydroxide, calcium hydroxide, silver hydroxide, ammonium hydroxide, magnesium hydroxide, sodium carbonate, sodium bicarbonate (also known as sodium hydrogen carbonate), and potassium carbonate.

The base may be added to the precursor composition in the form of a liquid, such as an aqueous or non-aqueous solution or suspension, or in the form of a solid, such as a powder.

The precursor composition comprises a mixture of tobacco particles and a pH adjuster. In embodiments where the tobacco particles and pH adjuster are dry, for example where the base is in the form of a dry powder, the pH of the precursor composition will be adjusted (compared to the pH of the tobacco particles without the pH adjuster) once water is added to the composition.

As used herein, the pH of the precursor composition or of the tobacco constituent releasing component refers to the pH once water is added to the composition or component where the composition or component is dry.

In some embodiments, the buffer system used to adjust the pH is a mixture of a weak base and its conjugate acid. Suitable buffer systems include, for example, ones having a pH of at least about 7.5, at least about 8, at least about 8.5 or at least about 9. In some embodiments, the pH of the buffer system is from about 8 to about 10, or from about 8.5 to about 9.5. Suitable buffer systems include, for example, those based on ammonia, carbonates or hydroxides, with suitable counterions. An example of a specific buffer system is a mixture of ammonia and ammonium chloride.

Tobacco Particles

The tobacco particles present in the precursor composition have a size small enough to ensure that multiple such particles can be agglomerated to form tobacco constituent releasing components having desired dimensions based upon their intended use.

Smaller tobacco particles have a greater surface area to volume ratio and they may therefore exhibit enhanced release of tobacco constituents compared to particles of larger sizes.

In addition, the size of the tobacco particles (and of other particles in the precursor composition) will have an effect on the porosity and density of the agglomerated structures and tobacco constituent releasing components. Thus, the size of the tobacco particles may be selected to produce a more porous agglomerated structure, which will have an impact on the release of the tobacco constituents. Thus, the size of the tobacco particles is another factor that may be adjusted in order to influence the release of tobacco constituents, in particular where the agglomerated structure is made by granulation as opposed to extrusion.

The preferred size of the tobacco particles may also depend upon the method used to form the agglomerated structures. For example, extrusion processes can be sensitive to the size of the particles within the composition being extruded. Specifically, in some embodiments where the precursor composition is extruded to form the agglomerated structure, it may be desirable for the particles in the precursor composition, including the tobacco particles, to have an average particle size of no greater than about 3 mm, of no greater than 1 mm, of no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, when measured by sieving.

In some embodiments, it may be desirable for the tobacco particles in the precursor composition and/or in the tobacco constituent releasing component to have an average particle size of no greater than about 3 mm, of no greater than 1 mm, of no greater than about 0.5 mm, or to have an average particle size of no greater than about 0.3 mm, when measured by sieving. In some embodiments, the average particle size is within the range of about 0.1 to about 3 mm, of about 0.1 to about 1 mm, of about 0.1 to about 0.5 mm, of about 0.1 to about 0.4 mm, or in the range of about 0.2 to about 0.3 mm. In some embodiments, at least about 90% of the particles of the precursor composition will have a particle size within the range of about 0.1 to about 3 mm, or of about 0.1 to about 1 m, or of about 0.1 to about 0.5 mm. In some embodiments, at least about 90% of the tobacco particles of the precursor composition will have a particle size within the range of about 0.1 to about 3 mm, or of about 0.1 to about 1 mm, or of about 0.1 to 0.5 mm. In some embodiments, none of the particles in the precursor composition have a particle size greater than 5 mm, greater than 4 mm, greater than 2 mm, greater than 1.5 mm, or greater than about 1 mm.

Particles of the desired size may be formed by grinding, shredding, cutting or crushing tobacco material. Suitable machinery to create such tobacco particles includes, for example, shredders, cutters, or mills, such as hammer mills, roller mills or other types of commercially available milling machinery. The size of the tobacco particles is selected to provide particles which can be readily prepared from a variety of different types of tobacco material, which can be formed into agglomerated structures using the processes described herein and having the properties described herein, and which provide a source of tobacco constituents that are readily released.

Without wishing to be bound by any one particular theory, it is speculated that the chopping of the tobacco to form the tobacco particles enhances the release of tobacco constituents including volatile flavours and aromatic constituents, as well as nicotine. The increased surface area of the tobacco particles is also thought to aid volatilisation. The smaller tobacco particles also improve the homogeneity of agglomerated structures formed therefrom together with other components.

The tobacco material used to form the tobacco particles may be any type of tobacco and any part of the tobacco plant, including tobacco lamina, stem, stalk, ribs, scraps and shorts or mixtures of two or more thereof. Suitable tobacco materials include the following types: Virginia or flue-cured tobacco, Burley tobacco, Oriental tobacco, or blends of tobacco materials, optionally including those listed here. The tobacco may be expanded, such as dry-ice expanded tobacco (DIET), or processed by any other means. In some embodiments, the tobacco material may be reconstituted tobacco material. The tobacco may be pre-processed or unprocessed, and may be, for instance, solid stems (SS); shredded dried stems (SDS); steam treated stems (STS); or any combination thereof. The tobacco material may be fermented, cured, uncured, toasted, or otherwise pre-treated.

Additional Components of Precursor Composition

The tobacco constituent releasing components having an agglomerated structure are formed from a precursor composition comprising tobacco particles.

In some embodiments, the precursor composition and/or the tobacco constituent releasing component does not include a binder or binding additive. In other embodiments, the precursor composition comprises a binder or binding additive. The binding additive may be selected to assist in the formation of an agglomerated structure by helping to adhere the tobacco particles to each other and to other components in the composition. Suitable binding additives include, for example, thermoreversible gelling agents such as gelatin, starches, polysaccharides, pectins, alginates, wood pulp, celluloses, and cellulose derivatives such as carboxymethylcellulose.

In some embodiments, the precursor composition and/or the tobacco constituent releasing component further comprises a diluent. The diluent may be in solid or liquid form. In some embodiments, the diluent is inert or substantially inert.

In some embodiments, the agglomerated structure formed from the precursor is composition may have an increased surface area by including in the precursor composition particles of an inert filler material. Suitable inert fillers may be porous or non-porous.

In some embodiments, the precursor composition and/or the tobacco constituent releasing component further comprises at least one aerosol forming agent which may be, for instance, a polyol aerosol generator or a non-polyol aerosol generator, preferably a non-polyol aerosol generator. It may be a solid or liquid at room temperature, but preferably is a liquid at room temperature. Suitable polyols include sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol. Suitable non-polyols include monohydric alcohols, high boiling point hydrocarbons, acids such as lactic acid, and esters such as diacetin, triacetin, triethyl citrate or isopropyl myristate. A combination of aerosol forming agents may be used, in equal or differing proportions. Glycerol and propylene glycol are particularly preferred.

In some embodiments, the the precursor composition and/or tobacco constituent releasing components may include a flavour-modifier, to modify the flavour provided by the tobacco particles or to add flavour. In some embodiments, the flavour-modifier may be included in the precursor composition. Alternatively or in addition, the flavour-modifier may be added to or applied to the agglomerated structure. Flavour-modifiers include, for example, casing materials, as well as “flavour” and “flavourant” materials which, where local regulations permit, may be used to create a desired taste or aroma in a product for adult consumers. They may include extracts (e.g., licorice, hydrangea, Japanese white bark magnolia leaf, chamomile, fenugreek, clove, menthol, Japanese mint, aniseed, cinnamon, herb, wintergreen, cherry, berry, peach, apple, Drambuie, bourbon, scotch, whiskey, spearmint, peppermint, lavender, cardamon, celery, cascarilla, nutmeg, sandalwood, bergamot, geranium, honey essence, rose oil, vanilla, lemon oil, orange oil, cassia, caraway, cognac, jasmine, ylang-ylang, sage, fennel, piment, ginger, anise, coriander, coffee, or a mint oil from any species of the genus Mentha), flavour enhancers, bitterness receptor site blockers, sensorial receptor site activators or stimulators, sugars and/or sugar substitutes (e.g., sucralose, acesulfame potassium, aspartame, saccharine, cyclamates, lactose, sucrose, glucose, fructose, sorbitol, or mannitol), and other additives such as charcoal, chlorophyll, minerals, botanicals, or breath freshening agents. They may be imitation, synthetic or natural ingredients or blends thereof. They may be in any suitable form, for example, oil, liquid, gel, wax or powder.

In some embodiments, the precursor composition and/or the tobacco constituent releasing component further comprises a preservative. Suitable preservatives would be readily known to the skilled person and would include, for example, those that are safe for use in products producing inhalable aerosols. Examples of preservatives that might be used include: propylene glycol, carvacrol, thymol, L-menthol, 1,8-cineole, phenoxyethanol, PhytoCide, sorbic acid and its salts, sodium hydroxymethylglycinate, ethylhexylglycerin, parabens and vitamins such as vitamin E or vitamin C.

In some embodiments, neither the precursor composition nor the tobacco constituent releasing component includes a gelling agent.

Form of Agglomerated Structures

In some embodiments, the tobacco constituent releasing components are in particulate form, being small, separate particles. In most embodiments, multiple particles will be incorporated into an apparatus in order to have the desired effect on the aerosol of the apparatus.

In some embodiment, the particulate tobacco constituent releasing components have an average size (as measured by sieving) of from about 0.5 mm to about 4 mm. In some embodiments, it may be preferable for the granules to have an average size of from about 0.7 mm to about 3 mm. Where, for example, the granules are to be dispersed within the filter material of a filter element (as in a Dalmatian style filter element), it may be preferable for the granules to have an average size of from about 0.3 mm to about 1 mm. Where, for example, the granules are to be included in a cavity, such as a cavity within a filter, it may be preferable for the granules to have an average size of from about 0.5 mm to about 4 mm.

In other embodiments, the tobacco constituent releasing components are in monolithic form, being larger articles. In most embodiments, a single monolithic component will be incorporated into an apparatus in order to have the desired effect on the aerosol of the apparatus.

In some embodiments, the monolithic components are roughly spherical or cylindrical in shape. They may have a diameter of from about 4 mm to about 10 mm. In some embodiments, the diameter may be from about 5 mm to about 8 mm. Cylindrical components may additionally have a length of from about 5 mm to about 80 mm, from about 15 mm to about 50 mm, or from about 20 mm to about 30 mm.

Forming the Agglomerated Structures

FIG. 1 is a flow chart showing the key steps in the processes of the present invention. The tobacco starting material, which may be pre-treated or pre-processed, is ground to the desired particle size. The pH is adjusted, either by adding one or more bases or by adding a buffer solution to the tobacco particles. Any additional components may be added to the tobacco material. These additional components may be in liquid form or is solid form. Additional solid components are preferably in particulate or powder form. The additional components may be added before, during or after the pH adjustment step. An agglomerated structure is then formed from the resultant precursor composition, by adhering the pH-adjusted tobacco particles and optional other components to form multi-particle entities.

In some embodiments, water may be added to the precursor composition as a processing aid. For example, the presence of water may help to dissolve components of the precursor composition, such as the pH adjusting agent and sugars, and/or it may assist with binding or improve agglomeration.

In some embodiments, the agglomerated structure may be formed from the precursor composition by a process including one or more steps selected from the group consisting of granulation, extrusion and spheronisation.

Granulation

Granulation of the precursor composition involves the binding or fusing together of the particles of the precursor composition to form larger, multi-particle entities which are referred to herein as agglomerated structures. The multi-particle entities formed by granulation are called granules and they may have various geometric shapes, including, for example, the general form of spheres, cylinders, and the like.

In one embodiment, the granulation step used is wet granulation. In wet granulation, granules are formed by the addition of a granulation liquid onto a powder bed. Agitation in the system, along with the wetting of the components within the precursor composition, results in the aggregation of the particles to produce wet granules. The granulation liquid may be at least partially removed by drying to provide dry granules. The granulation liquid may be water-based or solvent-based. Suitable granulation liquids include, for example, water, glycerol, ethanol and isopropanol, either alone or in combination. In some embodiments, the granulation liquid comprises an aerosol forming agent, such as glycerol or one of the other agents mentioned herein, and/or a binder or binding agent. In some embodiments, no water is added to the precursor composition to aid granulation.

In another embodiment, the granulation step used is dry granulation. In dry granulation, granules are formed without using a granulation liquid. This type of process has the advantage that it does not expose the precursor composition to moisture and so there is no requirement to expose the granules to heat in order to dry them. Forming granules by dry granulation involves compacting and densifying the precursor composition, usually under high pressure.

Extrusion

Extrusion of the precursor composition involves the feeding of the precursor composition through an orifice to produce an extruded agglomerate. The process, which applies pressure to the precursor composition combined with shear forces, results in agglomerated structures.

Extrusion may be performed using one of the main classes of extruders: screw, sieve and basket, roll, ram and pin barrel extruders. A single screw or twin screw extruder may be used. Forming the tobacco constituent releasing components by extrusion has the advantage that this processing combines mixing, conditioning, homogenizing and molding of the precursor composition.

In some embodiments, during extrusion the free-flowing precursor composition is exposed to elevated pressure and temperature and is forced though an orifice, such as a shaping nozzle or die, to form an extruded agglomerate. In some embodiments, the extruded agglomerate has a rod-like form and/or it may be cut into segments of a desired length as it exits the orifice. A rod-like extruded agglomerate may subsequently be cut into segments of desired length.

In some embodiments, the precursor composition comprising tobacco particles is exposed to temperatures from about 40° C. to about 150° C., or from about 80° C. to about 130° C., or from about 60° C. to about 95° C. within the extruder. In some embodiments, including those using double extrusion, the precursor composition is exposed to temperatures from about 70° C. to about 95° C. within the extruder. In some embodiments, including those using single extrusion, the precursor composition is exposed to temperatures from about 60° C. to about 80° C. within the extruder. The composition may be exposed to pressures (immediately before the die or nozzle) ranging from about 2 bar to about 100 bar, or from about 5 bar to about 60 bar, depending on the design of the die or nozzle being used.

In some embodiments, due to the relatively high density of the extruded agglomerate and the relatively open surface of the tobacco particles within it, the tobacco constituent releasing components formed from the extruded agglomerate exhibit good heat transfer and mass transfer, which has a positive impact on the release of tobacco constituents, such as flavours and nicotine.

In some embodiments, the extrusion may be a generally dry process, with the precursor composition being a dry or substantially dry material that includes tobacco particles, as well as optionally other particulate materials including, for example, base, diluent, solid aerosol forming agents, solid flavour modifiers, etc.

In some embodiments, liquids may be added to the precursor composition during the extrusion process. For example, water may be added to the precursor composition, for example as a processing aid to assist dissolution or solubilisation of components of the composition, or to aid binding or agglomeration. Alternatively or additionally, a wetting agent may be added to the precursor composition.

In some embodiments, the liquid may be an aerosol forming agent such as glycerol or others discussed herein. When liquid is added to the precursor composition in this manner, the liquid is applied not only on the surface, but, as a result of the extruder pressure combined with the intensive mixing by high shear forces, the extruded agglomerate becomes impregnated with the liquid. Where the liquid is an aerosol forming agent, this can result in a high availability of the aerosol forming agent in the agglomerated product to enhance evaporation of flavour components from the tobacco particles and other components of the agglomerated structure, enhancing release of tobacco constituents from the resultant extruded tobacco constituent releasing components.

In some embodiments, in view of the impregnation of the extruded agglomerate with the aerosol forming agent, greater volumes of this additive can be incorporated into the tobacco constituent releasing component than if the aerosol forming agent were simply being applied to the surface of the precursor composition or of the extruded agglomerate. In some embodiments, the amount of aerosol forming agent incorporated into the tobacco constituent releasing component may be at least about 1% by weight, at least about 1.5% by weight, at least about 2% by weight, at least about 3% by weight, at least about 5%, at least about 10%, at least about 15% or at least about 20% by weight.

In some embodiments, the amount of aerosol forming agent incorporated into the tobacco constituent releasing component may be up to about 30% by weight and even up to about 40% by weight. High amounts of aerosol forming agent, such as at least about 10% or at least about 20% by weight, may be advantageous where the tobacco constituent releasing component is to generate an aerosol in addition to releasing the tobacco constituents. Smaller amounts of aerosol forming agent, such as up to about 5% by weight, may be sufficient where the tobacco constituent releasing component's primary function is to releasing the tobacco constituents or other flavours carried by the components into an existing aerosol or air flow.

The extruded agglomerate will be shaped by the nozzle or die through which it is forced. In some embodiments, the extruded agglomerate is cut into pieces of desired length. The pieces formed in this way may be used as tobacco constituent releasing components or they may undergo further processing.

In some embodiments, the nozzle or die is shaped to provide a solid strand of extruded agglomerate. For example, the extruded agglomerate may have the form of a solid cylindrical rod. Alternatively, the extruded agglomerate may have different cross-sectional shapes, including oval, polygonal (such as triangular, square, etc.), and stars.

In some embodiments, the extruded composition is formed into a desired shape selected to enhance or promote the release of flavour, for example by providing a form having a large surface area per unit volume. This large surface area may be provided on the outer surface of the extruded agglomerate, for example by selecting cross-sectional is shapes with large perimeter. Alternatively or in addition, the large surface area may be provided through the creation of channels within the extruded agglomerate.

In some embodiments, the nozzle is shaped to provide an extruded agglomerate with inner channels. These inner channels provide further surface area and can enhance constituent release.

Examples of some nozzle designs are shown in FIGS. 2 a, 2 b and 2 c. These nozzles 1 have orifices 2 through which the extruded composition is forced to produce an extruded agglomerate with a cartwheel-like spoked structure. These nozzles are used in an extruder, as shown in FIGS. 2d and 2 e, in which the direction of the flow of the material being extruded is indicated by the arrow A.

FIG. 3 is a photograph of some extruded rod-shaped agglomerates, showing different cross-sectional geometries including inner channels. Some of these extruded agglomerates have been made using the nozzle designs of FIGS. 2 a, 2 b and 2 c.

FIG. 4a shows an example of a die used to produce granules by extrusion. This die 3 has multiple orifices 4 through which the extruded composition is forced to produce extruded agglomerates which exit the die in the form of a numerous solid cylindrical rods which are cut at the die to form extruded granules of the desired length. The diameter of the granules is driven primarily by the diameter of the orifice 4. Such a die can be used in an extruder, and the direction of the flow of the material being extruded is indicated by the arrow A in FIG. 4 b, which includes a side view of the die 3.

FIG. 5 is a schematic representation of some extruded agglomerates in the form of granules.

Tobacco constituent releasing components formed from such shaped extruded agglomerate sections have an inner channel structure which have advantageous adjustable strand ventilation properties and a significantly enlarged inner surface leading to improved heat and mass transfer. As a result, such components exhibit better, more uniform release of flavour by evaporation. Furthermore, the structure with inner channels exhibits significantly improved strength in both the radial and axial directions, which is beneficial for the further processing of the extruded agglomerate, for example when it is cut into segments.

By means of various nozzle or die designs and/or different process parameters within the extruder, including the temperature, pressure and shear forces, extruded agglomerates with different physical properties may be prepared, including different heat transfer properties, draft resistance, and capable of producing different aerosols and/or of modifying aerosols being drawn through the extruded agglomerate.

In some embodiments, the extruded agglomerate is shaped upon discharge from the extruder. In some embodiments, the extruded agglomerate is cut to an initial length, for example 1 metre, and allowed to cool before then being cut into sections of the desired length to provide tobacco constituent releasing components of the desired dimensions.

In some embodiments, the extruded agglomerate may be cooled just before or just as it leaves the extruder. In some embodiments, the cooling is intensive and involves exposing the extruded agglomerate, which will be at an elevated temperature, for example from about 30° C. to about 100° C., or from about 40° C. to about 70° C., to a cooling means that will reduce the temperature to within a range of from about 0° C. to about 70° C., from about 0° C. to about 50° C., from about 5° C. to about 25° C. or from about 5° C. to about 15° C. This rapid cooling of the extruded agglomerate may enhance the internal and external stability of the extruded agglomerate. In some embodiments, it is the nozzle or die that is cooled to achieve this effect.

In some embodiments, it may be desirable to control the temperature of the precursor composition during extrusion, including before feeding the composition through the nozzle or die. This is especially the case where the precursor composition includes temperature sensitive components, such as aerosol forming agents such as glycerol. Thus, in some embodiments, extrusion of the precursor composition includes reducing the temperature of the precursor composition before it reaches the nozzle or die. Such cooling of the precursor composition may result in the formation of an extruded agglomerate with beneficial properties, or may improve the strand-shaping process, for example where channels are to be formed within the extruded agglomerate strand.

In some embodiments, spheronisation is used to further process extruded segments. These segments are typically cylindrically-shaped and are cut or broken into uniform lengths following extrusion. They are then gradually transformed into spherical shapes is by spheronisation. This shaping occurs as a result of plastic deformation and spheronisation can lead to spherical agglomerated structures, often with a nearly uniform diameter.

Incorporation into an Apparatus

One or more tobacco constituent releasing components may be incorporated into an aerosol provision device, such as an apparatus for heating smokeable material to volatilise at least one component of the smokeable material.

As used herein, an aerosol provision device includes vapour devices such as e-cigarettes, devices for heating smokeable material such as tobacco heating devices and hybrid devices.

As used herein, the apparatus for heating smokeable material to volatilise at least one component of the smokeable material includes so-called “heat not burn” products or tobacco heating devices or products, which release compounds by heating, but not burning, smokeable material. It also includes other nicotine delivery products such as aerosol generation devices including e-cigarettes and Hybrid products, in which a liquid, such as a nicotine-containing liquid or a nicotine-free liquid, is heated to form an aerosol and this aerosol is then drawn through a smokeable material, such as a tobacco segment, picking up tobacco flavours or wherein a separate aerosol is formed by heating a smokeable material. The aforementioned apparatus may be provided with a filter for the aerosol drawn by the user.

The tobacco constituent releasing component may be positioned within the apparatus or device so that the tobacco constituents that are released become entrained in an aerosol generated by the apparatus or device upon use, modifying the properties of the aerosol, for example by imparting tobacco constituents, including tobacco flavour, to that aerosol. Additionally or alternatively, the tobacco constituent releasing component may itself generate an aerosol during use, said aerosol including the released tobacco constituents.

In some embodiments, an apparatus or device may be provided with a filter having tobacco constituent releasing component located within said filter. This may be in addition to or instead of the apparatus or device including other tobacco constituent releasing components.

In some embodiments the filter or filter element may comprise a filter material which has a filtering effect. Suitable filter material may include, for example, tow comprising or consisting of cellulose acetate, polylactic acid, and/or other suitable polymers, or the filter or filter element may comprise a hard material such as plastic with holes.

In some embodiments where multiple tobacco constituent releasing components are incorporated into a filter, this may be in a “Dalmatian” style filter section, where the tobacco constituent releasing components are dispersed throughout a fibrous filter plug material. Alternatively, the tobacco constituent releasing components may be located in a cavity within the filter. The cavity may, for example, be a cavity section positioned between two (or more) adjacent filter plugs or the cavity may be a pocket defined within a filter plug. In such embodiments, the tobacco constituent releasing components may be small in size, for example in the form of granules.

In other embodiments, a larger, single tobacco constituent releasing component is incorporated into a filter. For example, a single tobacco constituent releasing component may be embedded in a fibrous filter plug material.

Alternatively, the tobacco constituent releasing component may be incorporated into a multi-segment filter, the tobacco constituent releasing component itself making up one of the filter segments. In such embodiments, the tobacco constituent releasing component may have any shape or size, but it may be advantageous for the component to a have a cylindrical shape and the dimensions similar to or compatible with those of the filter segments. In some embodiments, the tobacco constituent releasing component may be surrounded by filter material such as a layer of fibrous filter tow, to form a filter segment. In other embodiments, the tobacco constituent releasing component may have the dimensions of a filter plug and it may be incorporated into a filter with one or more adjacent filter plugs. Alternatively, a tobacco constituent releasing component may be included in a cavity section positioned between two (or more) adjacent filter plugs.

In some embodiments the tobacco constituent releasing component itself may be the filter element in the aerosol provision device, it being capable of filtering condensates and other particulate matter in the aerosol, before the aerosol is inhaled by the user.

According to some embodiments, one or more tobacco constituent releasing components are included in an aerosol provision device or apparatus for heating smokeable material to volatilise at least one component of the smokeable material in which a tobacco segment is heated but not combusted (i.e., a tobacco heating product or so-called Heat-not-Burn product). In some of these products, the tobacco segment is heated to generate an aerosol.

One option is to incorporate the one or more tobacco constituent releasing components in the filter of such products. In some embodiments, multiple tobacco constituent releasing components are incorporated into the filter of a tobacco heating product. In other embodiments, a single tobacco constituent releasing component is incorporated into the filter of a tobacco heating product.

Another option is to incorporate one or more tobacco constituent releasing components in the tobacco segment of such products. In some embodiments, one or more tobacco constituent releasing components may be incorporated into tobacco material to form the tobacco segment. For example, the one or more tobacco constituent releasing components may be dispersed within the tobacco material, such as cut tobacco or reconstituted tobacco, to contribute to the flavour imparted by the tobacco. In other embodiments, the tobacco included in the tobacco segment of the tobacco heating product consists or consists essentially of one or more tobacco constituent releasing components. In one embodiment, the tobacco segment heated by the tobacco heating product consists of or consists essentially of one or more tobacco constituent releasing component. The tobacco constituent releasing component may be heated directly. Where the tobacco segment is multiple tobacco constituent releasing components, these may be held in a container or cartridge. At least portions of the container or cartridge may be permeable to air, to allow air to flow over or through the tobacco constituent releasing components.

FIG. 6 shows a cross-sectional view of an example of a tobacco heating product for heating a smokeable material. The apparatus ii has a heating chamber 14 which in use contains the smokeable material to be heated and volatilised. In this embodiment, the smokeable material is in the form of a monolithic tobacco constituent releasing component 13. The smokeable material could however be multiple tobacco constituent releasing components held in the heating chamber or provided in a cartridge like the one illustrated in FIG. 8.

The apparatus ii of FIG. 6 further has an electronics/power chamber 16 which may, for example, contain electrical control circuitry and/or a power source (not shown). The electrical control circuitry may include a controller, such as a microprocessor arrangement, configured and arranged to control the heating of the smokeable material via a heating element (not shown). The electrical control circuitry may in use receive a signal from for example a puff-actuated sensor which is sensitive to for example changes in pressure or changes in rate of air flow that occur upon initiation of a draw on the apparatus 11 by a user. The electrical control circuitry can then operate so as to cause heating of the smokeable material “on demand”. Various arrangements for a puff-actuated sensor are available, including for example a thermistor, an electro-mechanical device, a mechanical device, an optical device, an opto-mechanical device and a micro electro mechanical systems (MEMS) based sensor. As an alternative, the apparatus may have a manually operable switch for a user to initiate a puff.

The heating chamber 14 is contained within the housing 12. There may be a support and/or insulating means (not shown) positioned between the heating chamber 14 and the housing 12, for example to assist in heat-insulating the housing 12 from the heating chamber 14, so that the housing 12 does not become hot or at least too hot to touch during use.

The housing 12 includes an inlet 15 through which air is drawn into the apparatus. The housing 12 also includes an outlet 17 at a mouthpiece 18 of the apparatus 11. Air is drawn into the apparatus 11 through the inlet 15, travels through the apparatus picking up tobacco constituents released by the tobacco constituent releasing component 13, and the resulting aerosol generated by the apparatus 11 leaves the apparatus 11 through the outlet 19 and is inhaled by the user.

According to some embodiments, one or more tobacco constituent releasing components are included in a so-called Hybrid product for heating smokeable material to volatilise at least one component of a smokeable material. In some of these products, the tobacco segment is heated to generate an aerosol, in addition to the heating of a liquid, such as a nicotine-containing liquid or a nicotine-free liquid, which is heated by a heat source to form an aerosol or vapour. In some Hybrid products, the is aerosol or vapour formed from the liquid is drawn over or through the tobacco segment, picking up tobacco flavours. In other embodiments, the aerosol or vapour formed from the liquid is not drawn over or through the tobacco segment.

In Hybrid products that include a filter, one option is to incorporate the tobacco constituent releasing components in the filter of such products, in a similar manner to that described for tobacco heating products. In some embodiments, multiple tobacco constituent releasing components are incorporated into the filter of a Hybrid product. In other embodiments, a single tobacco constituent releasing component is incorporated into the filter of a Hybrid product.

Where the smoking article is a so-called Hybrid product another option is to incorporate the tobacco constituent releasing components in the tobacco segment of such products. In some embodiments, one or more tobacco constituent releasing components may be incorporated into tobacco material to form the tobacco segment. For example, the one or more tobacco constituent releasing components may be dispersed within the tobacco material, such as cut tobacco or reconstituted tobacco, to contribute to the flavour imparted by the tobacco. In other embodiments, the tobacco included in the tobacco segment of the Hybrid product consists of one or more tobacco constituent releasing components. In one embodiment, the tobacco segment in the Hybrid product consists of or consists essentially of one or more tobacco constituent releasing components.

FIG. 7 shows a cross-sectional view of an example of a Hybrid product for heating a smokeable material and a liquid. The apparatus 21 has a housing 22 containing a chamber 24 which in use contains the smokeable material to be heated and volatilised. In this embodiment, the smokeable material is in the form of a monolithic tobacco constituent releasing component 23. The smokeable material could however be multiple tobacco constituent releasing components held in the chamber or provided in a cartridge like the one illustrated in FIG. 8. The housing 22 also contains a liquid reservoir 25 containing a liquid 26 to be heated to form a vapour.

The apparatus 21 further has an electronics/power chamber 27 which may, for example, contain electrical control circuitry and/or a power source (not shown). The electrical control circuitry may include a controller, such as a microprocessor arrangement, configured and arranged to control the heating of the smokeable material is and of the liquid 26 via one or more heating elements (not shown). The electrical control circuitry may allow the apparatus 21 to be puff-actuated, so as to cause heating of the smokeable material “on demand”. As an alternative, the apparatus 22 may have a manually operable switch for a user to initiate a puff.

The housing 22 also includes an inlet 28 through which air is drawn into the apparatus. The housing 22 also includes an outlet 29 at a mouthpiece 30 of the apparatus 21. Air is drawn into the apparatus 21 through the inlet 28, travels through the apparatus picking up the vapour created by heating the liquid 26 in the liquid reservoir 25, and tobacco constituents released by the tobacco constituent releasing component 23, and the resulting aerosol generated by the apparatus 21 leaves the apparatus 21 through the outlet 29 and is inhaled by the user.

The Hybrid device 21 shown schematically in FIG. 7 represents just one possible configuration of such an apparatus. The relative positions of the liquid reservoir 25 and the smokeable material chamber 24 can be changed, as can the path of the air flowing through the apparatus.

In one embodiment, the liquid reservoir is positioned upstream of the smokeable material to be volatilised. Alternatively, the liquid reservoir may be positioned downstream of the smokeable material to be volatilised. In a yet further arrangement, the two sources of aerosol in the apparatus may be arranged side-by-side, etc.

In some embodiments, the vapour produced by heating the liquid in the liquid reservoir flows over or through the smokeable material comprising or consisting of one or more tobacco constituent releasing components. In some embodiments, the elevated temperature of the vapour causes the tobacco constituents to be released. Alternatively or in addition, the smokeable material may be separately heated by a heating means.

In some embodiments, a Hybrid device is provided in which the vapour created by heating a liquid heats the smokeable material in order to volatilise at least one component of the smokeable material. In some embodiments, the liquid is a nicotine-free liquid. In other embodiments, the liquid contains nicotine. Where the smokeable material is heated by the vapour to volatilise at least one component of the smokeable material, in certain embodiments the device does not include a separate means for heating the smokeable material. The smokeable material may comprise or consist of at least one tobacco constituent releasing component.

In other embodiments, the vapour produced by heating the liquid in the liquid reservoir does not flows over or through the smokeable material comprising or consisting of one or more tobacco constituent releasing components. Rather, this vapour and the aerosol generated by heating the smokeable material only mix after they are both formed.

The tobacco heating products and Hybrid products described herein may, in some embodiments, include tobacco segments in the form of containers or cartridges containing one or more tobacco constituent releasing components. These containers or cartridges may be removable. They may replace both the chamber holding the smokeable material and the smokeable material in the apparatus described above with reference to FIGS. 6 and 7, and in the alternative embodiments discussed.

Referring to FIG. 8, a tobacco segment cartridge 31 is shown, comprising a housing 32 defining a cavity within which are held one or more tobacco constituent releasing components according to the invention (not shown). The housing 32 may, for example be made from moulded plastic or the like. In order to allow air drawn through the device to pass into the cartridge 31 and over or through the one or more tobacco constituent releasing components and then out of the cartridge 31, ventilation holes 33 are provided in the housing 32 of the cartridge 31. In some embodiments, the cartridge 31 may further comprise heating means that is heatable by a suitable means in order to heat the one or more tobacco constituent releasing components held therein.

Hybrid Product

An apparatus is provided for heating smokeable material to volatilise at least one component of the smokeable material, and a nicotine-free liquid which is to be heated to form a vapour, wherein the smokeable material comprises tobacco particles having a basic pH, and wherein the smokeable material is heated by the vapour. This is a so-called Hybrid device.

In some embodiments, the apparatus includes a means for heating the liquid to form a vapour, but not including a separate means for heating the smokeable material. Thus, the heat to volatilise at least one component of the smokeable material comes from the vapour created by heating the nicotine-free liquid (the e-liquid, as it is often referred to as in such devices).

The tobacco particles are pH-adjusted. This may be achieved by adding a pH adjuster to the tobacco particles or to a composition including the tobacco particles. The pH may, for example, be increased by the addition of one or more bases or a basic buffer system. Any of the bases and buffer systems mentioned herein may be suitable. Furthermore, the pH may be adjusted to any of the pH values or ranges mentioned herein.

In some embodiments, the tobacco particles have an average diameter no greater than 3 mm, no greater than 1 mm, no greater than 0.5 mm, or no greater than 0.3 mm, as measured by sieving. Once again, the particle size may be as discussed above.

The smokeable material comprising the tobacco particles may include other materials.

In some embodiments, the smokeable does not include a binder or binding additive. In other embodiments, the smokeable material comprises a binder or binding additive. Suitable binding additives include, for example, thermoreversible gelling agents such as gelatin, starches, polysaccharides, pectins, alginates, wood pulp, celluloses, and cellulose derivatives such as carboxymethylcellulose.

In some embodiments, the smokeable material further comprises a diluent. The diluent may be in solid or liquid form. In some embodiments, the diluent is inert or substantially inert.

In some embodiments, the smokeable material further comprises at least one aerosol forming agent which may be, for instance, a polyol aerosol generator or a non-polyol aerosol generator, preferably a non-polyol aerosol generator. It may be a solid or liquid at room temperature, but preferably is a liquid at room temperature. Suitable polyols include sorbitol, glycerol, and glycols like propylene glycol or triethylene glycol. Suitable non-polyols include monohydric alcohols, high boiling point hydrocarbons, acids such as lactic acid, and esters such as diacetin, triacetin, triethyl citrate or isopropyl myristate. A combination of aerosol forming agents may be used, in equal or differing proportions. In some embodiments, glycerol and propylene glycol are particularly preferred.

In some embodiments, the smokeable material may include a flavour-modifier, to modify the flavour provided by the tobacco particles or to add flavour. Suitable flavour-modifiers are discussed in detail above.

In some embodiments, the smokeable material further comprises a preservative, as discussed above. In other embodiments, the smokeable material is free of any preservative.

In some embodiments, the smokeable material comprises tobacco particles in the form of one or more agglomerated structures, as discussed in detail above. Optionally, such agglomerated structures may be formed by extrusion.

In order to address various issues and advance the art, the entirety of this disclosure shows by way of illustration various embodiments in which the claimed invention(s) may be practiced and provide for superior tobacco constituent releasing components and smoking articles. The advantages and features of the disclosure are of a representative sample of embodiments only, and are not exhaustive and/or exclusive. They are presented only to assist in understanding and teach the claimed features. It is to be understood that advantages, embodiments, examples, functions, features, structures, and/or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the claims or limitations on equivalents to the claims, and that other embodiments may be utilised and modifications may be made without departing from the scope and/or spirit of the disclosure. Various embodiments may suitably comprise, consist of, or consist essentially of, various combinations of the disclosed elements, components, features, parts, steps, means, etc. In addition, the disclosure includes other inventions not presently claimed, but which may be claimed in future. 

1. A tobacco constituent releasing component for inclusion in an aerosol provision device, the tobacco constituent releasing component having an agglomerated structure formed from a precursor composition comprising tobacco particles, wherein the pH of the precursor composition has been adjusted to a basic pH.
 2. A component as claimed in claim 1, wherein the pH is increased by the addition of one or more bases or a basic buffer system.
 3. A tobacco constituent releasing component for inclusion in an aerosol provision device, the tobacco constituent releasing component comprising tobacco particles and one or more bases or a basic buffer system, the tobacco constituent releasing component having a basic pH.
 4. A component as claimed in claim 3, wherein the one or more base is selected from the group consisting of hydroxides, carbonates and hydrogen carbonates.
 5. A component as claimed in any one of claims 2 to 4, wherein the one or more base is selected from the group consisting of: potassium hydroxide, sodium hydroxide, sodium carbonate and sodium bicarbonate.
 6. A component as claimed in any one of the preceding claims, wherein the pH of the precursor composition is at least about 7.5.
 7. A component as claimed in any one of the preceding claims, wherein the tobacco particles have an average diameter no greater than 3 mm, no greater than 1 mm, no greater than 0.5 mm, or no greater than 0.3 mm.
 8. A component as claimed in any one of the preceding claims, further comprising one or more aerosol forming agent.
 9. A component as claimed in claim 8, wherein the aerosol forming agent is selected from the group consisting of glycerol, propylene glycol and glyceryl triacetate.
 10. A component as claimed in any one of the preceding claims, further comprising one or more binder.
 11. A component as claimed in claim 10, wherein the one or more binder is selected from the group consisting of: thermoreversible gelling agents, such as gelatin; starches; polysaccharides; pectins; celluloses; cellulose derivatives, such as carboxymethylcellulose; and alginates.
 12. A component as claimed in any one of the preceding claims, further comprising one or more flavour-modifier.
 13. A component as claimed in any one of the preceding claims, wherein the precursor composition is granulated or spheronised to form the agglomerated structure.
 14. A component as claimed in any one of the preceding claims, wherein the precursor composition is extruded to form the agglomerated structure.
 15. A component as claimed in any one of the preceding claims, in the form of granules.
 16. A component as claimed in any one of the preceding claims, having an elongated or rod-shaped form.
 17. A component as claimed in any one of the preceding claims, wherein having a cross sectional shape to increase the surface area of the tobacco constituent releasing component.
 18. An aerosol provision device comprising a tobacco constituent releasing component as claimed in any one of the preceding claims.
 19. A device as claimed in claim 18, wherein the device is a tobacco heating product comprising a tobacco segment which is to be heated to volatilise constituents, and optionally including a filter or filter element.
 20. A device as claimed in claim 18, wherein the device is a Hybrid product comprising a tobacco segment which is to be heated to volatilise constituents, and a liquid which is to be heated to form a vapour, and optionally including a filter or filter element.
 21. A device as claimed in any one of claims 18 to 20, wherein the tobacco constituent releasing component is located in a filter or filter element of the device.
 22. A device as claimed in claim 21, wherein one or more tobacco constituent releasing components are surrounded by filter material in the filter or filter element.
 23. A device as claimed in claim 21, wherein one or more tobacco constituent releasing components are located in a cavity of a multi-segment filter.
 24. A device as claimed in claim 19 or claim 20, wherein one or more tobacco constituent releasing components are located in the tobacco segment.
 25. A device as claimed in claim 24, wherein the tobacco segment consists of one or more tobacco constituent releasing components.
 26. A device as claimed in claim 18, wherein the device is a Hybrid product comprising a tobacco segment which is to be heated to volatilise constituents, and a liquid which is to be heated to form a vapour, wherein one or more tobacco constituent releasing components are located in the tobacco segment and wherein the tobacco segment is heated by the vapour.
 27. A device as claimed in claim 26, wherein the liquid is a nicotine-free liquid.
 28. A device as claimed in claim 26 or claim 27, wherein the device includes a means for heating the liquid to form a vapour, but does not include a separate means for heating the tobacco segment.
 29. A method of manufacturing a tobacco constituent releasing component, comprising preparing a precursor composition comprising tobacco particles; adjusting the pH of the precursor composition to a basic pH; and treating said precursor composition to form an agglomerated structure.
 30. A method as claimed in claim 29, wherein the precursor composition is granulated or spheronised to form the agglomerated structure.
 31. A method as claimed in claim 29, wherein the precursor composition is extruded to form the agglomerated structure.
 32. A method as claimed in claim 31, wherein the extruded agglomerate is cooled during or after extrusion.
 33. A method as claimed in claims 31 or claim 32, wherein the extrusion creates inner channels within the extruded agglomerate.
 34. An apparatus for heating smokeable material to volatilise at least one component of the smokeable material, and a nicotine-free liquid which is to be heated to form a vapour, wherein the smokeable material comprises tobacco particles having a basic pH, and wherein the smokeable material is heated by the vapour.
 35. An apparatus as claimed in claim 34, including a means for heating the liquid to form a vapour, but not including a separate means for heating the smokeable material.
 36. An apparatus as claimed in claim 34 or claim 35, wherein the pH is increased by the addition of one or more bases or a basic buffer system.
 37. An apparatus as claimed in any one of claims 34 to 36, wherein the pH of the tobacco particles is at least about 7.5.
 38. An apparatus as claimed in any one of claims 34 to 37, wherein the tobacco particles have an average diameter no greater than 3 mm, no greater than 1 mm, no greater than 0.5 mm, or no greater than 0.3 mm. 